In U.S. Pat. No. 4,804,663 there are described a number of 3-piperidinyl-1,2-benzisoxazoles substituted with a 4H-pyrido[1,2-a]pyrimidin-4-one moiety having antipsychotic activity.
The compounds of the present invention differ therefrom by the specific substitution on the 9-position of the 4H-pyrido[1,2-a]pyrimidin4-one moiety, and their improved antipsychotic properties, in particular their utility in treating acute psychoses.